CALIFORNIA 
AGRICULTURAL  EXTENSION  SERVICE 

CIRCULAR  17 
APRIL,  1928 


Liver  Fluke  and  Stomach 
Worm  of  Sheep 


STANLEY  B.  FREEBORN 


PUBLISHED  BY 

THE  COLLEGE  OF  AGRICULTURE 
UNIVERSITY  OF  CALIFORNIA 


Cooperative  Extension  work  in  Agriculture  and  Home  Economics,  College  of  Agriculture, 
University  of  California,  and  the  United  States  Department  of  Agriculture  cooperating.  Dis- 
tributed in  furtherance  of  the  Acts  of  Congress  of  May  8  and  June  30,  1914.  B.  H.  Crocheron, 
Director,  California  Agricultural  Extension  Service. 


UNIVERSITY  OF  CALIFORNIA  PRINTING  OFFICE 

BERKELEY.  CALIFORNIA 

1928 


Digitized  by  the  Internet  Archive 

in  2011  with  funding  from 

University  of  California,  Davis  Libraries 


http://www.archive.org/details/liverflukestomac17free 


LIVER  FLUKE  AND  STOMACH  WORM  OF  SHEEP 

STANLEY  B.  FREEBOENi 


LIVER  FLUKE 

Liver  fluke  of  sheep  and  cattle  is  becoming  an  increasingly  im- 
portant problem  in  California.  This  disease,  known  as  'Reaches," 
^' liver  rot/'  ''rotten  liver,"  and  ''flukes,"  as  well  as  by  its  tech- 
nical name  of  hepatic  distomiasis,  is  caused  by  a  flattened,  leaflike, 
brownish-gray  worm  about  one  inch  in  length  that  is  known  as 
Fasciola  hepatica. 

The  severity  of  the  disease  depends  on  the  condition  of  the  infested 
animal  and  the  number  of  flukes  that  it  is  harboring.  One  rancher 
on  the  Pacific  Coast  is  reported  to  have  lost  1,500  animals  last  year 
(1927).  The  economic  loss  entailed  by  the  animals  that  are  fatally 
attacked,  great  though  this  may  be,  is  but  a  part  of  the  total  loss. 
Animals  that  are  infested  even  moderately  fail  to  make  proper  weight, 
are  poor  mothers,  and  fall  easy  prey  to  diseases  such  as  pneumonia, 
hemorrhagic  septicaemia,  and  lung  worms.  Although  beef  cattle  are 
seldom  affected  as  severely  as  sheep,  the  loss  of  parasitized  livers 
condemned  at  the  slaughter  houses  on  account  of  fluke  lesions  amounts 
to  a  formidable  figure. 

Until  relatively  few  years  ago  it  was  believed  that  flukes  were 
endemic  only  along  the  Gulf  Coast  states  and  in  isolated  spots  along 
the  Pacific  Coast.  At  present  we  know  the  disease  to  be  present  on 
the  Pacific  Slope  in  Washington,  Oregon,  California,  Idaho,  Montana, 
Utah,  and  Colorado. 

THE    PARASITE 

Flukes  (fig.  1)  are  animals  belonging  to  a  queer  group  of  flat 
worms  known  as  trematodes.  They  are  leaflike  instead  of  rounded 
like  roundworms  or  elongated  like  tapeworms.  At  the  anterior  or 
wider  end  a  conical  projection  occurs;  this  supports  a  round  "sucker" 
or  pore  by  which  the  fluke  holds  itself  in  position.  On  the  lower 
surface  of  the  organism  at  the  base  of  this  projection  is  a  second  or 
ventral  sucker.  The  sheep  fluke  is  hermaphroditic,  i.e.,  both  male 
and  female  generative  organs  are  found  in  the  same  animal.  The 
male  elements  develop  first  and  later  disappear  to  make  room  for  the 
development  of  the  eggs,  which  finally  fill  the  fluke  body  completely. 


1  Associate  Professor  of  Entomology  and  Associate  Entomologist  in  the  Ex- 
periment Station. 


CALIFORNIA   AGRICULTURAL    EXTENSION    SERVICE 


[CiRC.  1' 


■■■^i^' 


Fig.  1.-  {a)  Adult  liver  fluke  enlarged  five  times.  Ventral  view,  {h)  Actual 
size  of  the  fluke  shown  in  (a).  Dorsal  view,  (c)  Adult  fluke  cleared  and  pre- 
pared for  microscopical  study,  showing  internal  anatomy.     X  5. 


LIFE    HISTORY 

The  adult  flukes  at  rest  in  the  larger  bile  passages  of  the  liver 
give  rise  to  myriads  of  eggs  which  pass  into  the  small  intestine  with 
the  bile  and  are  voided  with  the  feces  of  the  infested  animals.  The 
eggs  are  yellowish  and  thin-walled,  contain  numerous  embryonic  cells 
and  are  fitted  anteriorly  with  an  operculum  or  cap  to  facilitate  hatch- 
ing (fig.  2a).  The  embryo  (fig.  2&)  matures  very  rapidly  in  warm, 
moist  surroundings,  and  in  the  presence  of  moisture  it  hatches,  liberat- 
ing a  young  fluke  that  is  known  as  a  miracidium  (fig.  2c). 

The  miracidia  are  microscopic  in  size,  a  little  more  than  twice  as 
long  as  wide,  and  clothed  with  cilia  or  hairlike  structures  that  help 
it  to  swim  about  in  the  water.  The  minute  organisms  swim  about  in 
search  of  their  next  host  which,  if  we  are  to  accept  European  observa- 
tions as  applicable  to  American  conditions,  is  a  snail  of  the  genus 
Lymnaea.     This  genus  of  snails  is  characterized  by  its  cornucopia- 


1928] 


LIVER   FLUKE   AND    STOMACH   WORM    OF    SHEEP 


shape  and  by  having  its  opening  to  the  right  as  one  faces  the  opening. 
Burrowing  into  the  body  of  the  snail,  the  miracidium  settles  down  in 
the  tissue,  usually  in  the  pulmonary  chamber.  The  parasite  now  be- 
comes encysted  and  saclike  and  its  contents  divide  and  redivide  until 
the  sac  or  sporocyst  (fig.  2d)  contains  from  three  to  eight  separate 
cylindrical  organisms  known  as  rediae. 


x34^o 


X5+0 


XZ5-0 


XllS 


X11.J 


Fig.  2. — Developmental  stages  of  the  liver  fluke  that  take  place  outside  the 
body  of  the  sheep,  (a)  Egg  shortly  after  being  voided  from  the  sheep's  body 
with  the  feces;  (b)  egg  ready  to  hatch,  containing  the  fully  formed  miracidium; 
(c)  miracidium  attacking  the  body  wall  of  a  snail;  (d)  sporocyst  which  has  de- 
veloped from  the  miracidium  in  the  pulmonary  chamber  of  the  snail  and  contains 
developing  rediae;  (e)  redia  from  the  liver  of  the  snail  containing  developing 
cercariae;  (/)  free-swimming  cercaria  which  has  emerged  from  the  snail's  body. 
(Eedrawn  in  part  from  Thomas.) 


6  CALIFORNIA   AGRICULTURAL   EXTENSION    SERVICE  [CiRC.  17 

The  rediae  (fig.  2e)  now  begin  to  move  about  and  finally  rupture 
the  sporocyst  wall  and  migrate  to  some  other  organ  in  the  snail's  body, 
generally  the  liver.  The  reproductive  cells  in  the  body  of  each  redia 
now  begin  to  develop  and  soon  each  redia  gives  birth  to  from  eight  to 
ten  immature  flukes  known  as  cercariae  (fig.  2/) . 

These  cercariae  (approximately  300  for  each  original  miracidium 
that  entered)  leave  the  body  of  the  snail  and,  swimming  about  in 
water,  eventually  work  their  way  up  blades  of  grass  or  other  vegeta- 
tion. Certain  cells  on  the  surface  of  the  body  produce  a  tough, 
parchment-like  material  which  covers  the  body  of  the  cercaria  and 
glues  it  to  the  surface  of  the  vegetation.  Here  it  remains  alive  as 
long  as  a  small  amount  of  moisture  is  supplied  by  the  vegetation  upon 
which  it  is  encysted,  or  until  it  is  eaten  by  one  of  its  many  hosts, 
such  as  sheep,  cattle,  goats,  hogs,  rabbits,  horses,  mules,  or  even  man. 

When  eaten  by  its  primary  host,  the  cyst  is  quickly  dissolved,  and 
after  passage  through  the  stomach  the  young  fluke  burrows  through 
the  intestinal  mucosa,  wanders  about  the  body  cavity  for  a  time 
and  in  the  majority  of  cases  finally  attacks  the  liver,  burrowing 
through  the  capsule  and  functional  tissue  until  it  reaches  one  of  the 
minute  bile  capillaries  down  which  it  progresses  as  it  grows  older 
and  larger.  Eventually  the  bile  ducts  are  reached.  Here  the  fluke 
comes  to  maturity  and  liberates  eggs  over  long  periods  of  time — 
variously  estimated  at  from  six  to  twelve  months — after  which,  its 
function  in  life  accomplished,  it  flows  into  the  duodenum  with  the 
bile  and  is  voided  from  the  body  of  its  victim  in  a  partly  digested 
condition. 

THE    COURSE    OF    THE    DISEASE    IN    SHEEP    AND    CATTLE 

An  infestation  of  sheep  fluke  is  commonly  known  among  veterinar- 
ians as  distomiasis,  so-called  because  at  the  time  the  term  was  coined 
the  fluke  was  known  technically  as  Disiomum  hepaticum.  At  present 
the  technical  name  is  Fasciola  hepatica,  and  there  are  many  references 
in  the  literature  to  the  disease  as  fascioliasis. 

After  gaining  entrance  to  the  liver,  it  is  very  probable  that  the 
small  flukes  excrete  a  definite  poison  which  destroys  the  active  liver 
cells.  As  the  cells  break  down,  areas  of  dead  cells  often  become 
cavities,  and  these,  at  first  minute,  gradually  become  extended  until 
blood  vessels  are  tapped  and  more  or  less  serious  hemorrhages  are 
produced.  Sometimes  these  areas  may  progress  to  the  surface  of  the 
organ  and  by  draining  into  the  body  cavity  produce  acute  peritonitis. 
If  the  condition  does  not  become  serious  enough  to  produce  death  a 


1928]  LIVER   FLUKE   AND    STOMACH   WORM    OF    SHEEP  7 

chronic  state  of  inflammation  is  set  up.  Scar  tissue  then  forms  in 
much  g:reater  profusion  than  is  needed  for  actual  repair,  with  the 
result  that  the  bile  ducts  become  greatly  enlarged.  The  abnormal 
growth  of  this  tissue  in  the  supporting  framework  of  the  liver  causes 
a  condition  known  as  cirrhosis. 

At  autopsy,  the  first  point  that  will  be  noticed  is  the  swollen  con- 
dition of  the  bile  ducts,  which  often  stand  up  like  ropey  swellings  on 
the  surface  of  the  liver.  These  will  be  found  plugged  in  many  cases 
by  cheesy  masses  of  semi-solid  bile.  If  the  bile  ducts  are  found  in 
this  swollen  condition  it  is  generally  possible  to  find  adult  flukes 
present  also,  but  in  recovered  or  convalescent  cases  all  the  flukes  may 
have  matured  and  disappeared.  In  severe  cases  the  liver  tissue  has 
the  appearance  of  being  decomposed,  which  gives  the  name  ''liver 
rot."  This  condition  may  have  progressed  from  merely  slightly  dis- 
colored areas  to  the  almost  complete  supplanting  of  normal  liver  tissue 
by  masses  of  blood  in  various  stages  of  coagulation  and  decomposition. 

A  serious  condition  known  as  parasitic  anaphylaxis  is  often 
attributed  to  fluke  infestation  in  yearlings  and  aged  ewes.  The 
animals  affected  will  drop  out  of  the  flock  suddenly  and  stand  with 
lowered  head.  The  respiration  will  increase  rapidly,  diarrhea  will 
be  present,  the  temperature  becomes  sub-normal,  and  in  a  few  hours 
the  affected  animal  will  die  in  a  short  convulsion.  On  post-mortem 
examination  no  abnormal  conditions  will  be  found  except  the  presence 
of  minute  flukes,  scarcely  %  to  i/4  i^ch  in  length  in  the  liver,  and  old, 
healed  scars  of  a  previous  infestation  of  flukes.  It  is  believed  that 
the  shock  producing  death  is  caused  by  the  introduction  into  the  blood 
stream  of  the  toxin  or  poison  produced  by  the  young  flukes  and  its 
combination  or  reaction  with  some  substance  formed  by  the  previous 
infestation  of  flukes.    Fortunately  this  condition  is  rare. 

SYMPTOMS 

The  first  indication  of  infection  generally  manifests  itself  about 
a  month  after  infestation  with  the  cercariae.  A  tendency  to  lag 
behind  the  flock,  a  paling  of  the  exposed  mucous  membranes  and  a 
slight  edema  or  watery  swelling  beneath  the  jaw  and  under  the  eyes 
are  all  that  may  be  noted  at  this  time.  Curiously  enough,  the  animal 
apparently  gains  weight  during  this  period.  This  is  explained  by  the 
increased  flow  of  bile  caused  by  the  invasion  of  the  parasites.  This 
increased  bile  in  turn  facilitates  the  digestion  and  assimilation  of  fats. 

Shortly  after  this  first  preliminary  manifestation,  the  length  of 
time  depending  on  the  severity  of  the  infestation,  the  gain  in  weight 


8  CALIFORNIA   AGRICULTURAL   EXTENSION    SERVICE  [CiRC.  17 

stops  and  a  loss  is  noticeable.  The  animal  becomes  more  languid,  the 
watery  swelling  under  the  jaw  becomes  more  pronounced  and  pen- 
dulous and  may  be  accompanied  by  an  extensive  edema  under  the 
eyes  and  along  the  belly.  The  so-called  "black"  diarrhea  may  be 
present.  The  animal  entirely  loses  its  appetite.  Fatal  cases  terminate 
apparently  in  exhaustion.  The  duration  of  the  disease  is  exceedingly 
variable  but  very  rarely  exceeds  six  months,  death  or  recovery  having 
ensued  in  the  meantime. 

TREATMENT 

A  thorough  discussion  of  the  different  ''cures"  that  have  been 
suggested  from  time  to  time  would  be  too  lengthy  for  a  circular  of 
this  kind;  consequently  a  statement  of  the  methods  known  to  be  of 
economic  importance  is  all  that  will  be  attempted. 

Male  Fern. — In  1884,  Grassi  and  Calandruccio,  two  Italian  investi- 
gators, reported  favorable  results  from  the  use  of  male  fern  in  sheep 
affected  with  liver  flukes.  Several  years  later  patent  preparations 
of  male  fern  appeared  in  many  European  countries  under  trade 
names  and  since  that  time  the  literature  is  filled  with  references  to 
male-fern  treatment  under  the  disguises  of  ' '  Filmaron, "  ' '  Fasciolin, ' ' 
' '  Avisciolina, "  ''Danistol,"  and  "Distol" — all  male-fern  extractions 
containing  approximately  22  to  26  per  cent  filicine,  the  active  agent 
in  the  male-fern  preparations. 

Extensive  trials  of  male-fern  extract  in  the  British  Isles  have 
show^n  it  to  be  effective  against  adult  flukes  and  to  afford  adequate 
treatment  in  cases  where  the  infestation  was  not  too  heavy.  In  these 
latter  cases  death  was  sometimes  caused  in  lambs  by  the  hordes  of 
immature  flukes  too  small  to  be  reached  by  the  male-fern  treatment. 

The  recommended  method  of  treatment  is  to  administer  4  grams 
(1  teaspoonful)  of  extract  of  male  fern  containing  25  per  cent  filicine 
in  10  cc  (21/2  teaspoonfuls)  of  nonpurgative  oil  on  five  successive 
mornings  at  least  two  hours  before  the  animal  is  allowed  to  feed. 

Kamala. — Crude  kamala  had  been  used  for  many  years  as  a  general 
vermifuge.  Its  rated  efficiency  was  not  high,  however,  on  account 
of  the  small  dosages  of  the  crude  drug  generally  recommended.  After 
the  advent  of  male  fern  considerable  impetus  was  added  to  its  sale 
and  use  by  the  work  of  Marek,  who  reported  very  favorably  on  its 
use  as  compared  with  other  types  of  treatment.  It  was  recommended 
by  Hall  that  the  crude  drug  be  given  as  follows :  "To  yearlings 
and  older  sheep  give  15  grams  divided  into  two  doses  of  7.5  grams 
(2  drams)   each,  and  given  at  12-  to  24-hour  intervals.     The  entire 


1928]  LIVER   FLUKE   AND    STOMACH   WORM    OF    SHEEP  9 

15  grams  may  be  given  in  one  dose  to  a  strong  animal  or  divided  into 
five  doses  for  weak  ones.  After  treatment  sheep  are  dull  for  3  to  5 
days,  they  lie  down  a  great  deal,  eat  little  or  may  stop  eating  for 
a  day  or  two,  and  have  a  diarrhea.  The  flukes  are  said  to  die  in 
3  to  8  days." 

Corhon  Tetrachloride. — In  1921  Hall  of  the  United  States  Depart- 
ment of  Agriculture  proposed  the  use  of  carbon  tetrachloride  (CCI4) 
as  an  anthelmintic  for  intestinal  roundworms.  In  1926  Montgomerie 
in  Wales  reported  that  carbon  tetrachloride  was  an  efficient  agent  in 
the  destruction  of  adult  flukes.  Doses  of  one-half  cubic  centimeter 
administered  in  capsules  effected  a  complete  eradication  of  adult 
worms.  Later  work  led  to  the  general  recommendation  of  the  admin- 
istration of  one  cubic  centimeter  for  all  sheep.  Only  the  pure  drug 
is  used,  since  the  commercial  grade  is  far  less  effective.  Seddon  in 
New  South  Wales  has  administered  the  dosage  of  one  cubic  centimeter 
diluted  with  four  cubic  centimeters  of  liquid  petrolatum  as  a  drench, 
but  the  experience  in  this  country  is  limited  to  the  capsule  method 
of  administration. 

Soft  gelatin  capsules  each  containing  one  cubic  centimeter  of  the 
carbon  tetrachloride  are  now  procurable.  These  are  administered 
by  means  of  a  capsule  "gun"  or  long  forceps.  No  preliminary  fasting 
is  necessary.  Shaw  and  Sims  in  Oregon  report  very  satisfactory 
results  with  carbon  tetrachloride  for  liver-fluke  infestation  in  goats 
and  have  since  extended  their  work  to  sheep  with  highly  efficient 
results.  Thousands  of  sheep  have  now  been  treated  in  Oregon  and 
California  and  no  word  of  failure  has  been  published.  The  simplicity 
of  treatment  and  its  apparent  success  leave  little  to  be  sought  in  the 
way  of  treatment.  It  can  be  administered  throughout  pregnancy 
with  safety.  Tetrachlorethylene  (C2CI4)  which  has  largely  supplanted 
carbon  tetrachloride  for  intestinal  worms  is  not  effective  for  flukes. 

One  of  the  main  contraindications  for  administering  carbon  tetra- 
chloride to  human  beings  has  been  the  presence  of  liver  lesions. 
Consequently  it  was  with  some  doubt  that  the  drug  was  first  used 
in  a  sheep  disease  where  liver  lesions  are  the  most  prominent  defects 
noticeable.  However,  the  results  of  treatment  have  shown  no  un- 
toward effects  in  sheep,  although  cattle  are  reported  to  show  toxic 
results  in  some  cases  when  treated  with  this  drug  for  liver  fluke. 

The  answer  to  this  variability  was  doubtless  explained  in  Minot's 
work  with  dogs.  He  found  in  dogs  with  a  low  calcium  content,  that 
approximately  twelve  hours  after  administration  of  carbon  tetra- 
chloride the  animals  died  with  all  the  symptoms  of  infantile  tetany 
caused  by  lack  of  calcium.     Various  bile  pigments  such  as  bilirubin 


10  CALIFORNIA   AGRICULTURAL   EXTENSION    SERVICE  [CiRC.  17 

are  known  to  combine  with  calcium  in  the  blood;  in  fact,  this  is  a 
normal  procedure  wherein  the  calcium  in  the  blood  protects  the  body 
from  excess  of  bile.  However,  calcium  when  combined  with  bilirubin 
is  no  longer  available  to  the  body,  and  if  there  is  no  ionized  or  free 
calcium  available  the  animal  suffers  from  calcium  deficiency  and  dies 
in  tetany.  It  is  also  known  that  the  administration  of  carbon  tetra- 
chloride produces  an  abnormal  amount  of  bilirubin  in  the  blood.  He 
was  able  to  restore  dogs  to  a  normal  condition  in  a  few  moments  by 
injecting  calcium  chlorid  intravenously.  Cattle  are  apparently 
drained  of  their  available  calcium  far  more  readily  than  are  sheep, 
and  consequently  the  bilirubin  poured  into  the  blood  stream  by  the 
action  of  the  drug  combines  with  the  small  available  supply  of  calcium 
more  completely  than  is  the  case  with  sheep  that  apparently  have  a 
larger  reserve  of  calcium.  It  is  possible  that  sheep  pastured  on 
stubble  and  hay  pasturage  free  from  legumes  might  be  reduced  in 
calcium  to  the  point  where  carbon  tetrachloride  would  be  toxic. 
Attempts  to  produce  this  condition  artificially  are  now  being  con- 
ducted at  this  station. 

To  summarize  the  recommendations  for  treatment,  it  appears  that 
sheep  may  be  treated  for  liver  fluke  with  safety  and  efficiency  by  the 
administration  of  one  cubic  centimeter  of  carbon  tetrachloride  in 
capsules,  observing  the  necessary  care  not  to  break  the  capsule  in  the 
mouth,  where  the  fumes  could  be  inspired.  Calcium  deficiency  is  not 
as  important  in  sheep  as  in  cattle.  The  latter  are  susceptible  to 
calcium-deficiency  tetany  following  treatment  with  carbon  tetra- 
chloride and  should  be  treated  with  care  by  a  veterinarian  and  only 
after  reinforcing  their  feed  with  assimilable  calcium  such  as  marl 
for  at  least  a  week.  In  treating  sheep  or  goats  that  have  not  had 
access  to  pasturage  or  feed  containing  legumes,  such  as  bur  clover, 
alfalfa,  or  other  source  of  calcium  it  is  well  to  make  a  preliminary 
treatment,  under  the  observations  of  a  veterinarian,  of  a  few  trial 
animals. 

PREVENTION 

''Permanent  pastures  perpetuate  pernicious  parasites"  is  a  jingle 
that  every  flockmaster  should  take  as  his  litany  and  heed  as  no  other 
great  truth  of  his  industry.  In  the  days  of  the  wide  ranges  the 
infestation  of  the  pasture  with  parasitic  eggs  and  larvae  was  so 
scattered  that  the  parasites  that  obtained  a  host  were  few,  and  infesta- 
tions of  severe  nature  were  consequently  very  scattered.  With  our 
present  practice  of  small  permanent  ranges,  which  are  often  over- 
stocked, the  infective  forms  of  the  parasite  become  concentrated  in 


1928]  LIVER   FLUKE   AND    STOMACH   WORM    OF   SHEEP  11 

relatively  small  areas,  and  it  is  almost  impossible  to  avoid  infestation 
of  the  host  animals.  Infestation  probably  occurs  throughout  the  year 
in  California,  although  late  summer  seems  to  be  the  commonest  time. 

Attempts  have  been  made  to  rid  the  ranges  of  snails  by  adding 
copper  sulfate  (bluestone)  to  the  standing  v^ater  present  at  the  rate 
of  one  part  of  the  sulfate  to  a  million  parts  of  water  (one  ounce  to 
7,800  gallons)  and  repeating  at  the  end  of  a  month  to  kill  those 
snails  that  have  hatched  in  the  interval,  but  this  is  impractical  under 
most  California  conditions. 

Some  owners  have  decreased  the  amount  of  infestation  remarkably 
on  relatively  dry  ranges  by  fencing  off  the  marshy  areas  and  supply- 
ing water  in  elevated  troughs.  Wherever  this  procedure  is  practical 
it  pays  large  dividends,  because  not  only  fluke  but  stomach-worm, 
lung-worm,  and  intestinal-worm  infestations  have  their  origin  in 
marshy  areas  and  stagnant  pools. 


STOMACH  WORMS 

California  sheepmen  have  congratulated  themselves  for  years  that 
"stomach  worms,"  probably  the  greatest  single  enemy  of  sheep  in 
the  United  States,  was,  for  some  unknown  reason,  absent  from  Cali- 
fornia. For  several  years  reports  of  infestations  that  were  indicative 
of  stomach  worms  have  been  received,  but  no  actual  specimens  were 
identified  at  the  Experiment  Station  from  California  until  1927, 
when  specimens  from  four  separate  localities  were  found  to  be  true 
stomach  worms.  Since  that  time  numerous  reports  verified  by  compe- 
tent veterinarians  have  been  received,  indicating  that  this  infestation 
is  becoming  a  common  source  of  trouble  in  California. 

THE    PARASITE 

The  stomach  worm  of  sheep,  Haemonchics  contortus,  is  a  slender, 
hairlike  roundworm  found  in  the  fourth  stomach.  The  females  are 
approximately  one  inch  in  length  with  a  backward-directed  flap 
covering  the  genital  opening,  which  is  located  one-fifth  the  length  of 
the  worm  from  the  tail  end.  The  males  are  shorter  (%  to  %  inch) 
with  two  rounded  lobes  at  the  posterior  end  of  the  body,  which  are 
strengthened  by  six  fingers  or  ribs  in  each;  in  addition,  the  right 
lobe  bears  at  its  base  a  small  accessory  lobe  with  a  bifurcated  rib. 
The  females  have  a  peculiar  twisted  arrangement  of  the  genital  tubes 
which  shows  through  the  integument,  giving  a  spirally-banded  effect. 


12  CALIFORNIA   AGRICULTURAL   EXTENSION    SERVICE  [CiRC.  17 

The  general  color  of  these  parasites  ranges  from  a  pure  white  to  blood 
red,  the  average  specimens  appearing  pinkish  as  they  are  seen  at 
autopsy. 

The  stomach  worm  of  cattle,  Ostertagia  ostertagi,  has  been  reported 
from  sheep  and  confused  with  the  sheep  stomach  worm.  The  former 
is  brown,  not  over  one-half  inch  in  length  and  hairlike  in  thickness. 


LIFE    HISTORY 

Adult  females  in  the  fourth  stomach  of  the  sheep  produce  eggs, 
which  pass  to  the  exterior  with  the  feces  of  the  animal.  In  the 
presence  of  water  these  eggs  develop  and  hatch  as  motile  larvae,  after 
which,  without  growing  larger,  their  skin  is  molted  but  is  not  cast 
off,  thus  producing  the  so-called  'ensheathed  larva,'  which  is  the 
infective  stage  of  the  parasite.  The  time  necessary  for  the  production 
of  this  stage  ranges  from  approximately  three  days  at  95°  F  to  three 
weeks  at  50°  F.  The  ensheathed  larva  may  float  about  in  stagnant 
water  or  crawl  up  on  grasses  to  await  the  time  when  it  is  eaten  by 
another  host. 

Sheep  are  the  normal  hosts,  but  goats  and  cattle  have  also  been 
found  to  be  infested. 

COURSE   OF   THE    DISEASE 

Infested  animals  exhibit  the  same  general  symptoms  seen  in  fluke 
disease,  except  that  there  is  no  preliminary  gain  in  weight.  The 
emaciation  is  progressive,  the  mucous  membranes  become  pale,  edema 
is  noticeable  in  the  'bottle-jaw'  swelling  under  the  jaw,  and  the 
animal  refuses  to  eat,  dying  in  a  condition  of  extreme  emaciation. 

At  autopsy  in  cases  of  heavy  infestation  the  entire  contents  of 
the  fourth  stomach  may  appear  to  be  in  writhing  motion  from  the 
wriggling  of  the  worms.  In  lesser  infestations  it  is  sometimes  neces- 
sary to  flood  the  walls  of  the  organ  with  clear  water  after  washing 
over  the  contents  to  detect  the  parasites  adhering  to  the  mucosa.  In 
nearly  every  case  the  tiny,  bright  red  pin  points  on  the  mucosa  (lining 
of  the  stomach)  will  indicate  the  presence  of  these  parasites  because 
they  change  their  feeding  points  at  frequent  intervals,  leaving  these 
marks  as  evidences  of  their  points  of  attachment. 


1928]  LIVER   FLUKE   AND    STOMACH   WORM    OF    SHEEP  13 


TREATMENT 

A  one-per-cent  solution  of  copper  sulfate  (bluestone)  in  water 
(14  pound  to  3  gallons)  administered  as  a  drench  in  doses  of  100  cc 
(approximately  3  ounces)  to  yearlings  and  older  sheep  and  50  cc  to 
lambs  over  three  months  of  age  forms  a  very  satisfactory  treatment. 
In  heavily  infested  territory  this  must  be  repeated  every  month  as 
long  as  the  mean  temperature  remains  above  50°  F.  Use  only  bright 
blue  crystals,  discarding  any  that  have  turned  white.  Crush  these 
and  add  to  some  of  the  water  that  has  been  heated.  When  completely 
dissolved  add  the  remainder  of  the  water.  Do  not  use  exposed-metal 
containers.  Allow  three  gallons  of  the  solution  for  each  hundred 
adult  sheep. 

The  actual  administration  is  most  easily  accomplished  with  a 
rubber  tube,  enamel-ware  funnel  and  a  small  cup  holding  a  single 
dose.  The  funnel  is  fitted  into  the  outer  end  of  the  tubing  to  receive 
the  dosage.  The  end  which  is  placed  in  the  sheep's  mouth  may  be 
fitted  with  a  piece  of  metal  tubing  or  passed  through  a  wooden  block 
1  in.  X  4  in.  to  prevent  the  animal  from  biting  down  on  the  flexible 
tubing.  The  tubing  is  often  stapled  to  a  post  at  a  convenient  height 
with  enough  left  free  at  its  lower  end  to  facilitate  treatment.  By 
dipping  a  cupful  (choose  a  small  cup  holding  100  cc  or  mark  the 
100  cc  volume  on  a  larger  cup)  from  an  open  container  and  pouring 
it  into  the  funnel  after  the  tubing  has  been  adjusted  into  the  mouth 
of  the  animal  considerable  speed  may  be  developed  in  treatment. 
Outfits  which  depend  on  passing  the  solution  through  a  graduated 
glass  cylinder  by  means  of  pinchcocks  are  perhaps  slightly  more 
accurate  where  many  lambs  are  included  in  the  treatment. 

In  treating,  allow  the  animal  to  stand  in  a  normal  position  with 
its  head  parallel  with  the  ground.  Do  not  tilt  the  muzzle  up  as  this 
may  prevent  the  animal  from  swallowing  and  allow  the  solution  to 
enter  the  windpipe. 


14  CALIFORNIA   AGRICULTURAL   EXTENSION    SERVICE  [CiRC.  17 


PREVENTION 

Marshy  swales,  seepage  areas,  or  stagnant  water  in  some  form  are 
absolutely  essential  to  the  growth  of  the  parasite  from  the  time  the 
egg  leaves  the  sheep's  body  until  it  becomes  an  ensheathed  larva. 
The  sources  of  infestation  are  more  apparent  under  California  con- 
ditions than  elsewhere  on  account  of  the  lack  of  summer  rainfall. 
It  is  self-evident  that  if  sheep  could  be  restrained  from  frequenting 
such  areas  by  fencing  them  off,  reinfestation  would  be  prevented  auto- 
matically. If  this  is  done  and  drinking  water  supplied  in  elevated 
troughs  the  latter  must,  of  course,  be  so  constructed  that  they  do  not 
overflow  and  produce  a  muddy  bog. 

In  many  cases  this  procedure  is  impractical  and  pasture  rotation 
becomes  the  only  available  procedure.  At  temperatures  below  50°  F 
a  change  of  pasture  every  month  is  sufhcient,  but  as  the  temperature 
rises  it  is  necessary  to  move  more  frequently  until  at  95°  F  it  is 
possible  to  use  the  same  area  only  three  or  four  days.  Put  the  lambs 
on  the  cleanest  pasture  as  they  are  more  seriously  affected  than  the 
older  animals. 

Cultivation  apparently  destroys  the  infective  larvae.  Cattle 
should  not  follow  infested  sheep,  as  they  too  are  subject  to  infestation. 
Hogs  and  horses  are  apparently  not  affected. 


STATION   PUBLICATIONS   AVAILABLE   FOK  FEEE   DISTRIBUTION 


BULLETINS 


No.  No. 

253.  Irrigation   and   Soil   Conditions  in  the  3  86. 

Sierra    Nevada   Foothills,    California. 

262.  Citrus   Diseases   of   Florida   and    Cuba  3  87. 

Compared  with   those  of   California.  388. 

263.  Size  Grades  for  Ripe  Olives. 

268.   Growing  and  Grafting  Olive  Seedlings.  389. 

273.   Preliminary  Report  on  Kearney  Vine-  390. 

yard     Experimental     Drain,     Fresno 
County,    Calif.  391. 

277.  Sudan  Grass. 

278.  Grain   Sorghums.  392. 

279.  Irrigation  of  Rice  in  California.  393. 
283.  The  Olive  Insects  of  California.  394. 
304.   A  Study  of  the  Effects  of  Freezes  on 

Citrus  in  California. 

310.   Plum  Pollination.  395. 

313.  Pruning      Young      Deciduous      Fruit 

Trees.  396. 

324.   Storage  of  Perishable  Fruits  at  Freez- 
ing Temperatures.  397. 

328.   Prune    Growing  in    California. 

331.   Phylloxera-resistant  Stocks.  398. 

335.   Cocoanut    Meal    as    a    Feed    for    Dairy  400. 

Cows   and   Other  Livestock.  402. 

340.   Control     of     the     Pocket     Gopher     in  404. 

California.  405. 

343.  Cheese   Pests  and   Their   Control.  406. 

344.  Cold    Storage   as    an    Aid   to    the   Mar-  407. 

keting  of  Plums,  a  Progress  Report. 

347.  The  Control  of  Red  Spiders  in  Decid- 

uous Orchards.  4  08. 

348.  Pruning  Young  Olive  Trees.  409. 

349.  A    Study    of    Sidedraft    and    Tractor 

Hitches. 

350.  Agriculture     in      Cut-Over      Redwood 

Lands.  410. 

353.  Bovine    Infectious    Abortion,    and    As- 

sociated Diseases  of  Cattle  and  New- 
born  Calves.  411. 

354.  Results  of  Rice  Experiments  in  1922. 

357.  A    Self-Mixing    Dusting    Machine    for  412. 

Applying  Dry  Insecticides  and  Fun- 
gicides. 

358.  Black    Measles,     Water    Berries,     and  414. 

Related  Vine  Troubles. 

361.  Preliminary  Yield   Tables  for  Second-  415. 

Grovv^h   Redwood.  416. 

362.  Dust  and  the  Tractor  Engine. 

363.  The  Pruning  of  Citrus  Trees  in  Cali-  417. 

fornia. 

364.  Fungicidal    Dusts    for   the    Control    of  418. 

Bunt. 

366.  Turkish     Tobacco     Culture,     Curing,  419. 

and   Marketing. 

367.  Methods  of  Harvesting  and  Irrigation  420. 

in  Relation  to  Moldy  Walnuts. 

368.  Bacterial      Decomposition      of      Olives  421. 

During  Pickling.  422. 

369.  Comparison     of     Woods     for     Butter 

Boxes.  423. 

370.  Factors    Influencing   the    Development 

of  Internal  Browning  of  the  Yellow  424. 

Newton   Apple. 

371.  The   Relative    Cost   of   Yarding    Small  425. 

and   Large  Timber.  426. 

373.  Pear   Pollination. 

374.  A    Survey    of    Orchard    Practices    in  427. 

the     Citrus     Industry     of     Southern 
California.  428. 

375.  Results   of   Rice   Experiments   at   Cor- 

tena,   1923,  and  Progress  in  Experi- 
ments in  Water  Grass  Control  at  the  429. 
Biggs   Rice   Field    Station,    1922-23.  430. 
377.   The  Cold  Storage  of  Pears.  431. 

379.  Walnut   Culture  in   California. 

380.  Growth    of    Eucalyptus    in    California  432. 

Plantations. 
382.   Pumping    for    Draininge    in    the    San  433. 

Joaquin   Valley,    California. 
385.   Pollination  of  the  Sweet  Cherry. 


Pruning  Bearing  Deciduous  Fruit 
Trees. 

Fig    Smut. 

The  Principles  and  Practice  of  Sun- 
Drying  Fruit. 

Berseem  or  Egyptian  Clover. 

Harvesting  and  Packing  Grapes  in 
California. 

Machines  for  Coating  Seed  Wheat 
with   Copper   Carbonate   Dust. 

Fruit  Juice  Concentrates. 

Crop   Sequences  at  Davis. 

I.  Cereal  Hay  Production  in  Cali- 
fornia. II.  Feeding  Trials  with 
Cereal  Hays.    ' 

Bark  Diseases  of  Citrus  Trees  in  Cali- 
fornia. 

The  Mat  Bean,  Phaseolus  Aconitifo- 
lius. 

Manufacture  of  Roquefort  Type  Cheese 
from  Goat's  Milk. 

Orchard    Heating   in    California. 

The  Utilization  of  Surplus  Plums. 

The  Codling  Moth  in  Walnuts. 

The  Dehydration  of   Prunes. 

Citrus    Culture   in    Central    California. 

Stationary  Spray  Plants  in  California. 

Yield,  Stand,  and  Volume  Tables  for 
White  Fir  in  the  California  Pine 
Region. 

Alternaria   Rot  of  Lemons. 

The  Digestibility  of  Certain  Fruit  By- 
Products  as  Determined  for  Rumi- 
nants. Part  I.  Dried  Orange  Pulp 
and  Raisin  Pulp. 

Factors  Influencing  the  Quality  of 
Fresh  Asparagus  after  it  is  Har- 
vested. 

Paradichloi'obenzene  as  a  Soil  Fumi- 
gant. 

A  Study  of  the  Relative  Value  of  Cer- 
tain Root  Crops  and  Salmon  Oil  as 
Sources   of   Vitamin    A  for   Poultry. 

Planting  and  Thinning  Distances  for 
Deciduous  Fruit  Trees. 

The  Tractor  on  California  Farms. 

Culture  of  the  Oriental  Persimmon  in 
California. 

Poultry  Feeding:  Principles  and  Prac- 
tice. 

A  Study  of  Various  Rations  for  Fin- 
ishing Range  Calves    as  Baby  Beeves. 

Economic  Aspects  of  the  Cantaloupe 
Industry. 

Rice  and  Rice  By-Products  as  Feeds 
for  Fattening  Swine. 

Beef   Cattle  Feeding  Trials,    1921-24. 

Cost  of  Producing  Almonds  in  Cali- 
fornia :   a  Progress  Report. 

Apricots  (Series  on  California  Crops 
and   Prices). 

The  Relation  of  Rate  of  Matui-ity  to 
Egg  Production. 

Apple  Growing   in  California. 

Apple  Pollination  Studies  in  Cali- 
fornia. 

The  Value  of  Orange  Pulp  for  Milk 
Production. 

The  Relation  of  Maturity  of  Cali- 
fornia Plums  to  Shipping  and 
Dessert  Quality. 

Economic  Status  of  the  Grape  Industry. 

Range  Grasses  of  California. 

Raisin  By-Products  and  Bean  Screen- 
ings as  Feeds  for  Fattening  Lambs. 

Some  Economic  Problems  Involved  in 
the  Pooling  of  Fruit. 

Power  Requirements  of  Electrically 
Driven    Manufacturing    Equipment. 


No. 
434. 

435. 


436. 
437. 
438. 
439. 


BULLETINS — (Continued) 
No. 


Investigations  on  the  Use  of  Fruits  in 

Ice  Cream  and  Ices. 
The      Problem      of      Securing      Closer 
Relationship     Between     Agricultural 
Development     and     Irrigation     Con- 
struction. 
I.   The   Kadota   Fig.      II.   Kadota   Fig 

Products.  . 

Economic  Aspects  of  the  Dairy  In- 
Grafting  Affinities  with  Special  Refer- 
ence to  Plums.  .  „  .,  -r. 
The  Digestibility  of  Certain  Fruit  By- 
products as  Determined  for  Rumi- 
nants. Part  II.  Dried  Pineapple 
Pulp,  Dried  Lemon  Pulp,  and  Dried 
Olive  Pulp. 


440. 


441. 
442. 
443. 

444. 

445. 


The  Feeding  Value  of  Raisins  and 
Dairy  By-Products  for  Growing  and 
Fattening  Swine. 

The  Electric  Brooder. 

Laboratory  Tests  of  Orchard  Heaters. 

Standardization  and  Improvement  of 
California   Butter. 

Series  on  California  Crops  and  Prices  : 
Beans. 

Economic  Aspects  of  the  Apple  In- 
dustry. 


No. 
87. 
115. 
117. 

127. 
129. 
136. 

144. 

157. 
164. 
166. 
173. 

178. 
179. 

202. 

203. 
209. 
212. 
215. 
217. 

230. 

231. 
232. 

234. 

238. 
239. 

240. 

241. 

243. 

244. 
245. 

248. 

249. 
250. 

252, 
253, 
254. 

255, 


CIRCULARS 
No. 


Alfalfa. 

Grafting  Vinifera  Vineyards. 

The    selection    and    Cost    of    a    bmall 

Pumping   Plant. 
House  Fumigation. 
The  control  of  Citrus  Insects. 
Melilotus    Indica    as    a    Green-Manure 

Crop  for  California. 
Oidium    or    Powdery    Mildew    of    the 

Vine. 
Control  of  Pear   Scab. 
Small   Fruit   Culture   in   California. 
The   County  Farm  Bureau. 
The    Construction    of   the    Wood-Hoop 

Silo.  .      ^  Tj. 

The  Packing  of  Apples  m  California. 

Factors  of  Importance  in  Producing 
Milk  of  Low  Bacterial  Count. 

County  Organization  for  Rural  Fire 
Control. 

Peat   as   a  Manure   Substitute. 

The  Function  of  the  Farm  Bureau. 

Salvaging   Rain-Damaged   Prunes. 

Feeding   Dairy   Cows  in    California. 

Methods  for  Marketing  Vegetables  in 
California.  ,    ^^  .       ,^.,, 

Testing  Milk,  Cream,  and  Skim  Milk 
for  Butterfat. 

The   Home  Vineyard.  r,  ^^e       • 

Harvesting  and  Handhng  California 
Cherries   for    Eastern    Shipment. 

Winter  Injury  to  Young  Walnut 
Trees  During  1921-1922. 

The   Apricot  in    California.  _ 

Harvesting  and  Handling  Apricots 
and  Plums  for  Eastern  Shipment.  _ 

Harvesting  and  Handling  California 
Pears  for  Eastern  Shipment. 

Harvesting  and  Handling  California 
Peaches  for  Eastern   Shipment.     _ 

Marmalade  Juice  and  Jelly  Juice 
from   Citrus  Fruits. 

Central  Wire  Bracing  for  Fruit  Trees. 

Vine  Pruning   Systems.^ 

Some  Common  Errors  in  Vine  Prun- 
ing and  Their  Remedies. 

Replacing  Missing  Vines. 

Measurement  of  Irrigation  Water  on 
the  Farm. 

Support  for   Vines. 

Vineyard   Plans.     „  .  ,    ^  .  ,.     .      j^ 

The  Use  of  Artificial  Light  to  In- 
crease Winter  Egg   Production. 

Leguminous  Plants  as  Organic  Fer- 
tilizers in   California   Agriculture. 


257. 

258. 
259. 
261. 
264. 

265. 
266. 

267. 

269. 

270. 
273. 
276. 

277. 

278. 
279. 
281. 


282. 

283. 
284. 
286. 
287. 
288. 
289. 
290. 
292. 
293. 
294. 
296. 

298. 

300, 
301. 
302. 
304. 
305, 
306, 

307, 
308, 
309 
310 

311 


The  Small-Seeded  Horse  Bean  (Vicia 
faba   var.   minor). 

Thinning   Deciduous   Fruits. 

Pear  By-Products. 

Sewing  Grain  Sacks. 

Preliminary  Essentials  to  Bovine  Tu- 
berculosis Control  in   California. 

Plant   Disease  and   Pest   Control. 

Analyzing  the  Citrus  Orchard  by 
Means  of  Simple  Tree  Records. 

The  Tendency  of  Tractors  to  Rise  in 
Front;   Causes  and  Remedies. 

An   Orchard   Brush   Burner. 

A  Farm   Septic  Tank. 

Saving  the   Gophered  Citrus  Tree. 

Home    Canning. 

Head,  Cane  and  Cordon  Pruning  of 
Vines. 

Olive  Pickling  in  Mediterranean 
Countries.  . 

The  Preparation  and  Refining  of 
Olive  Oil  in  Southern  Europe. 

The  Results  of  a  Survey  to  Deter- 
mine the  Cost  of  Producing  Beef  m 
California. 

Prevention  of  Insect  Attack  on  Stored 
Grain. 

Fertilizing  Citrus  Trees  in  Cahfornia. 

The   Almond  in   California. 

Milk  Houses  for  California  Dairies. 

Potato   Production  in    California. 

Phvlloxera  Resistant  Vineyards. 

Oak  Fungus  in   Orchard  Trees. 

The  Tangier  Pea. 

Alkali   Soils.  ^        ,     ^.     .. 

The    Basis   of   Grape    Standardization. 

Propagation   of   Deciduous   Fruits. 

Control  of  the  California  Ground 
Squirrel.  , 

Possibilities  and  Limitations  of  Coop- 
erative Marketing. 

Coccidiosis  of   Chickens. 

Buckeye  Poisoning  of  the  Honey  Bee. 

The    Sugar   Beet  in   California. 

Drainage  on  the  Farm. 

Liming  the   Soil. 

A  General  Purpose  Soil  Auger  and 
Its  Use   on  the  Farm. 

American   Poulbrood   and   Its   Control. 

Cantaloupe    Production    in    California. 

Fruit  Tree   and   Orchard  Judging. 

The  Operation  of  the  Bacteriological 
Laboratory  for  Dairy  Plants. 

The  Improvement  of   Quality  in  Figs. 


The  publications  listed  above  may  be  had  by  addressing 

College  of  Agriculture, 

University  of  California, 

Berkeley,  California 

12m-4,'28 


